茶碱对聚苯胺尿酸酶电极的生物电化学活性的抑制

用聚苯胺尿酸酶电极研究了茶碱对固定酶的影响，结果表明，茶碱对固定尿酶酶有明显的抑制作用，但这种抑制作用是可逆的，在茶碱的存在下，ＰＨ对酶电极的响应电流影响与无茶碱存在时不同；在０．２－０．５Ｖ之间，酶电极的响应电流随电位加而迅速升高，当电位进一步升高时，其变化速度减慢，茶碱使尿酶酶催化反应的活化能从无抑制剂存在的时的２９．９ｋＪ．ｍｏｌ＾－１提高到４７．８ｋＪ．ｍｏｌ＾－１，即抑制剂改变了尿酸催化

Inhibition of Bioelectrochemical Activities of Polyaniline Uricase Electrode by Theophylline

The effect of theophylline on the immobilized enzyme has been investigated using polyaniline uricase electrode. The activity of the immobilized uricase is markedly inhibited by theophylline. However, this is a reversible inhibition. In the presence of theophylline, the effect of pH on the response current of the enzyme electrode is different from that without theo-phylline, the response current of the enzyme electrode rapidly increase with increasing potential from 0.20-0.50V, and then increases slowly with further increasing potential. The activation en-ergy of the enzyme-catalyzed reaction is 47.8kJ.mol-1 in the presence of theophylline, which is much larger than that without theophylline (29.9kJ.mol-1). This indicates that the path of the enzyme-catalyzed reaction was changed by theophylline.